Pressure-gage.



PATENTED MAR. 21, 1905.

C. E. SARGENT. PRESSURE GAGE. APPLIOATION FILED sBPT.z4.19o4.

www w// //N Patented March121 1905.

PATENT OFFICE.

CHARLES E. SARGENT, OF CHICAGO, ILLINOIS.

PRESSURE-GAGE.

SPECIFICATION `formingpart of Letters Patent ilo. 785,438, dated March21, 1905.

Application filed September 24, 1904. Serial No. 225,734.

To all whom it may concern:

Be it known that I, CHARLES E. SARGENT, a citizen of the United Statesof America, residing at Chicago, in the county of Cook and State ofIllinois, have invented certain new and useful Improvements inPressure-Gages, of which the following is a specification.

My invention relates to certain new and useful improvements inpressure-gages; and its object isto produce a device of this class whichshall have certain advantages, which will appear more fully and at largein the course of this specification.

To this end my invention consists in certain novel features, which aredescribed herein and illustrated in the accompanying drawing, whichrepresents a vertical section through my improved device.

'minating just above the bottom of the chamber. An inlet-pipe A opensinto the mercury-chamber at one side. Acap B is screwed over the top ofthe mercury-chamber, and the said cap, together with the said top of themercurychamber,forms a compression-chamber. A tube C extends through thecap B into the compression-chamber and is held in place by packing c,held under compression by a thimble C. The tube C is provided at its topwith a bulb D and along its side with a plurality of contact-points E. Aplug F is provided to give access to the chamber, and a contact-point G,entering the liquid, is secured to the mercury-chamber.

In practice the mercury-chamber Ais filled with mercury approximately tothe level of the bottom of the compression-chamber, and pressure isapplied to the inlet-pipe A. As the pressureincreases it is transmittedby the mercury to the air in the compression-chamber, tube, and bulb,which of course is compressed, in accordance with Boyles law, affordingaspace for the rise of the mercury in the compression chamber. Themercury reaches the lower end of the tube C just before the pressurewhich the gage is intended to indicateV is reached. As the pressureincreases from this point the mercury rises very rapidly through thelength of the tube and passesin succession the contact-points therein,any or all of which may be connected with electrical apparatus, asdesired. Still further increase of pressure will cause the mercury toenter the comparatively large bulb at the top of the tube, and itsfurther rise will become very slow indeed.

My im proved device is particularlydesigned for use and in connectionwith automatic sprinklers and the like, where-it is necessary that acontinuous high pressureof water be maintained. The parts are arrangedso that the normal pressure holds the mercury just within the bulb andkeeps the electrical circuit closed. If for any reason the pressure isdiminished, the mercury falls in the tube and opens the circuit, therebystarting the pumps, which raise the pressure until the circuit isclosed.l

The tube C is made adjustable in the cornpression-chamber, so that thepoint at which the mercury reaches the tube can be varied to.accommodate the device to systemsof standard pressure.

In some cases it may be desirable to prevent the grounding of theelectrical circuit through the water of the pressure system. To producethis result, it is desirable that the water be removed from contact withthe mercury, and this is accomplished by means of a chamber H,interposed between the inlet-pipe A and the water-pipes of the system.This chamber, it will be seen, has a long tube t, which is practically acontinuation of the inlet-pipe A', and a pipe L is provided at the lowerfend. of the chamber H, which can be connected with one of thewater-pipes of the pressure system. The pressure of the water will thenbe transmitted through the air in the chamber H to the mercury, andthewater itself will never come in! contact with lthe mercury. Thechamber H is made of suflcient size that the water will never rise abovethe end of the tube t, and the upper end of the chamber H is constrictedat the end H to prevent water from splashing over the end of the tube,and so reaching the mercury.

It will be evident that many variations in IOO the construction of mydevice are possible and that any desired liquid can be substituted formercury, although I greatly prefer mercury on account of its superioradvantages as an electrical conductor. My device is particularlyadvantageous because of the fact that the device is of small size, andthe rapid movement of the indicating medium is obtained at and near thepoint when accurate indication is desirable and comparatively slowmovement is obtained elsewhere.

I realize that considerable variation is possible in the details of thisconstruction without departing `from the spirit of the invention, and Itherefore do not intend to limit myself to the .specific form hereinshown and described.

I claim as new and desire to secure by Letters Patent- 1. In a device ofthe class described, the combination with a chamber for containingliquid and an inlet-pipe opening into the same, of a compression-chamberopening into the lower part of the said liquid-chamber, containing atube extending upward from said compression-chamber, and a comparativelylarge bulb at the upper end of said tube.

2. In a device of the class described, the combination with 'a chamberfor containing liquid and an inlet-pipe opening into the same, of acompression-chamber opening into the lower part of saidliquid-containing chamber, a tube of small diameter extending from thetop of said compression-chamber, and a comparatively large bulb attlieupper end of said tube.

3. In a device of the class described, the combination with aliquid-containing chamber and an inlet-pipe opening into the same, of acompression-chamber above the liquid -eontaining chamber, a tubeextending downward from the bottom of the compression-chamber to thelower part of the liquid-containing chamber, a tube ofismall diameterextending from the upper part of the compression-chamber, and a bulb atthe end of said second tube.

4. In a device of the class described, the combination with aliquid-containing chamber and an inlet-pipe opening into the same, of acompression chamber above the liquidcontaining chamber, a tube extendingdownward from the bottom of the compression-chamber to the lower part ofthe liquid -containing chamber; a tube of small diameter extending fromthe upper part oi' the compression-chamber, a bulb at the end of saidsecond tube, and means for adjusting said second tube within said compression-chamber.

5. In a device of the class described, the combination with amercury-chamber and inlet-pipe opening into the same, ot' acompression-chamber above the mercary-chamber, a tube extending downwardfrom the compression-chamber to the lower part of the mercury-chamber, atube extending upward from the upper part of the compression-chamber, acontact-point in the second tube, and a bulb at the upper end of thesecond tube.

6. In a device of the class described, the

combination with a mercury-chamber and inlet-pipe opening into the same`ot' a compression-chamber above the mercury-chamber, a tube extendingdownward from the compression-chamber to the lower part of the inerf'eury-chamber, a tube extending upward from the upper part ot' thecompressionchamber, a plurality of contact-points in the second tube,and a bulb at the upper end ot' the second tube.'

7. In a device of the class described, the combination with amercury-chamber, and an inlet-pipe opening into the same, oi' acompression-chamber above the mercury-chamber, a tube extending'downward from the compression-chamber to the lower part oi themercury-chamber, a tube extending upward from the upper part of themercuryichamber, a contact-point in the second tube, a bulb at the upperend of the second tube, an inletpipe opening into the mercury-chamber,an air-chamber opening into the said inletpipe and a tube communicatingwith the inlet-pipe, and extending to the top of the air-chamber.

In witness whereo' I have signed the above application for LettersPatent, at Chicago, in

the county of Cool; and State of Illinois, this.

21st day of September, A. I). 1904.

CHARLES E: SARGENI.

lVitnesses:

RUSSELL Wines, CHAS. SHEHVEY.

